1. Field Of the Invention
The present invention relates to a liquid crystal display device and, more in particular, to a liquid crystal display device of an In-Plane Switching mode.
2. Description of the Prior Art
In recent years, it is well known that the liquid crystal displays used in portable equipment including portable phones and the like have been designed highly efficient and highly functional. Such liquid crystal display devices are thin and lightweight, and are widely used as flat panel displays having low power consumption. Above all, the liquid display devices of a lateral electric field type (In-Plane Switching mode) are formed on an active matrix substrate, and generate a lateral electric field between a pixel electrode and a counter electrode that are mutually opposed.
The liquid crystal display devices of the In-Plane Switching mode perform a display in such a manner as to rotate the liquid crystal held between the active matrix substrate and the counter substrate almost in a horizontal direction to the substrate flat surface so as to perform displays. Accordingly, from the operation mode, wide display properties in the angle of visibility are obtained, thereby expanding utilization fields.
The conventional liquid crystal display device of a lateral electric field type was disclosed in Japanese Patent Laid-Open No. 2001-033821, for example.
The active matrix substrate and the counter substrate are formed with necessary constituent elements, respectively and, after that, are formed with orientation films, respectively. On this orientation film, a rubbing processing is performed to determine an initial orientation direction of the liquid crystal display. Further, a black matrix layer is provided on the counter substrate so that an unnecessary leaked light from a display picture element region is shielded and no orientation defect portion of the liquid crystal display such as discrimination and the like is visualized.
When a uniformity of the rubbing processing is low and the rubbing processing is not sufficiently performed, there occurs a light leak, and contrast properties are reduced. Further, there occurs the light leak due to a pattern of the black matrix layer of the counter substrate.